In various types of surgical procedures, medical devices are implanted at locations within the human body that are neither susceptible to direct visualization by the surgeon nor accessible by the surgeon's fingers. Such procedures are therefore performed using endoscopes for visualization and endoscopic instruments for carrying out the procedures. Once such procedure is the implantation of satiation devices used to limit volume of food intake and/or control feeling of hunger in patients suffering from obesity. In a preferred approach, such devices are passed through the esophagus into the stomach and are then secured within the stomach using sutures, clips, staples, adhesives etc. The tools and methods described herein are useful for introducing satiation devices into the stomach and for manipulating the devices into the appropriate implant position, and will thus will be described in that context. It should be understood, however, that these tools and methods may also be well suited for use with other types of medical implants and/or in other areas of the body.
An anatomical view of a human stomach S and associated features is shown in FIG. 1. The esophagus E delivers food from the mouth to the proximal portion of the stomach S. The z-line or gastro-esophageal junction Z is the irregularly-shaped border between the thin tissue of the esophagus and the thicker tissue of the stomach wall. The gastro-esophageal junction region G is the region encompassing the distal portion of the esophagus E, the z-line, and the proximal portion of the stomach S.
Stomach S includes a fundus F at its proximal end and an antrum A at its distal end. Antrum A feeds into the pylorus P which attaches to the duodenum D, the proximal region of the small intestine. Within the pylorus P is a sphincter that prevents backflow of food from the duodenum D into the stomach. The middle region of the small intestine, positioned distally of the duodenum D, is the jejunum J.
Implant devices for use in controlling obesity are shown and described in U.S. application Ser. No. 09/940,110, filed Aug. 27, 2001 and U.S. application Ser. No. 10/118,289 filed Apr. 8, 2002, U.S. Provisional Application No. 60/379,306 filed May 10, 2002, and U.S. application Ser. No. 10/345,666, filed Jan. 16, 2003 entitled SATIATION POUCHES AND METHODS OF USE. These applications are owned by the assignee of the present application, and the disclosures of these applications are incorporated herein by reference. One type of satiation device described in these applications is a prosthetic pouch positionable in the proximal stomach as shown in FIG. 2. The pouch 2 includes a proximal opening 4 and a smaller distal opening 6 and forms a small reservoir that collects masticated food from the esophagus—thereby limiting the amount of food that can be consumed at one time. As the pouch fills with food, it may distend, imparting pressure against the upper stomach and lower esophageal sphincter causing the patient to experience sensations of fullness. The pouch is fixed in place using clips, sutures or similar means 8 at anchor points around the perimeter of the proximal opening 4. Wire anchor loops 9 are preferably provided for receiving sutures or clips, although the pouch could also be secured to tissue using sutures, staples, clips, etc passed directly through the pouch walls. Alternatively, windows 7 may be formed in the pouch for receiving sutures during attachment of the pouch to adjacent tissue.
Optimal performance of the pouch is achieved when substantially all of the food ingested by the patient passes into the pouch. However, because of the flexible nature of the tissue of the gastro-esophageal junction region and/or the material forming the pouch, gaps can occur between the proximal perimeter of the pouch and adjacent tissue in regions between neighboring anchor points. Food entering or accumulating in the pouch can ooze from these gaps and pass around the exterior of the pouch directly into the stomach, thereby decreasing the effectiveness of the prosthesis. It is thus desirable to attach the pouch in a position and at an orientation that minimizes formation of gaps between anchor points.